The present invention relates to a technique for performing transfer of at least one of ink and air existing at least in a tube, which connects an ink tank and a recording head in an inkjet recording apparatus, regardless of variations in dimension corresponding values of the tube (for example, a diameter of the tube, a length of the tube, an inner volume of the tube, a flow path resistance in the tube (a pressure loss)), in a manner in accordance with the variations in the dimension corresponding values of the tube.
There is a known inkjet recording apparatus provided with an ink supply system of tube supply type. Specifically, such an inkjet recording apparatus includes a carriage and a main tank. On the carriage a recording head and a sub tank are mounted. The recording head ejects ink from an ejection nozzle to perform recording on a recording medium. The sub tank stores ink to be supplied to the recording head. The main tank stores ink to be supplied to the sub tank. In the inkjet recording apparatus, when the ink in the sub tank decreases, the ink in the main tank is supplied to the sub tank through a tube.
In the above inkjet recording apparatus, a viscosity of ink accumulated in the ejection nozzle and a tube in the recording head gradually increases. Therefore, there has been devised an inkjet recording apparatus of this type that periodically performs a purge operation in order to expel ink accumulated in the ejection nozzle and the tube of the recording head.